Benghal Dayflower (Commelina benghalensis L.) Seed Viability and Impact On Dispersal.

Benghal dayflower (Commelina benghalensis L.) is an invasive, noxious weed that is a serious threat to agriculture in the southeastern U.S.  Tolerance to glyphosate and the ability to produce both aerial and subterranean seeds and to regenerate from stem fragments make it extremely difficult to control. The purpose of this series of experiments is to establish ecological characteristics and viability potential of Benghal dayflower seeds.

The first set of experiments was designed to estimate  seed survival and viability in soil after an extended period of burial. Buried seeds collected over a period of years showed a steady decline in viability. After four years, no viable seeds were recovered. In a second set of experiments, aerial Benghal dayflower seed germination and viability were compared to that of five common weed species after exposure to simulated rumen digestion. Seeds were tested at intervals from 12 to 96 hours. Seeds from each of the other weeds tested were negatively impacted by digestion after 48 and 96 hours. In contrast, the same exposure increased the germination of Benghal dayflower seeds at 48 hours, with only a slight decrease after 96 hours.

In the last set of experiments, temperature data from a hay bale was collected for a period of two months after harvest. The temperatures were then simulated in germination chambers. Seed viability was tested periodically from one to 21 days. Seeds were non-viable after one day at 65 °C, and after 14 days at 50 or 45 °C.  The results provide important understanding of seed ecology that must be considered in attempts to eradicate Bengal dayflower in agricultural fields.